Which standard governs the testing of Type B or BW vents?

The testing of Type B or BW vents is governed by the UL 441 standard. This standard specifically outlines the requirements for the construction and performance of venting systems for gas-burning appliances and is essential to ensure safety and efficiency in venting practices. The guidelines established in UL 441 provide criteria for the materials, design, and performance characteristics needed for these vent systems to function safely under various operational conditions.

Utilizing industries standards like UL 441 is critical because it helps to ensure that manufacturers produce reliable venting products and that installations comply with safety regulations, ultimately protecting the end-users and the integrity of the HVAC systems they are part of.